BMW 530d Using Water...?

[ScottHughes]

Hi all,
My BMW 530d overheated 2 days ago and when inspected had hardly any water in it.. after a top up she has been ok but I keep having to top up the expansion tank...? any ideas... head gasket?

Help...

[Neil.D]

Yes this is a sympton of the head gasket going. How many miles on the clock?
Silly question im sure but always good to check the obvious first, does the expansion tank cap still have a good seal? Maybe a rubber washer has come out.

[ScottHughes]

Ummm Thought so.. is this common on the 530d..?

121,000 on the clock, the expansion tank seals etc are fine...

Thanks

[disco1]

9 times out of ten overheating is caused by faults not relating to gaskets.

Make sure your seals and pipes are okay, check your expansion tank has no cracks (this happened to mine) and renew with high ratio coolant, water alone disapears very quickly as it literally boils away.

Water/coolant has a funny was of escaping, sometimes hardley noticible to the eye, get the engine up to heat then spend a while checking for drips or wet patches.

[ScottHughes]

Hi all,
Thanks for advise it was the water pump... but now all the leaking water has seized the aircon belt tentioner..Doh..